This invention relates to a concrete paving machine, more particularly a machine for levelling concrete, of the type whereby poured concrete is spread over a predetermined width and this concrete is equalled at a well-defined thickness.
As known, such concrete paving machines are applied for spreading and equalling of concrete, with the intention of forming a floor, plate, road or similar, whereby either or not simultaneously certain profilings can be provided in the formed road, such as a drain, an upstanding edge, a concrete crash barrier, or similar.
It is known that such concrete paving machines generally are composed of a movable frame under which a number of tools is fixed, the aim of which is to distribute the concrete poured in front of the machine, more or less equalling it, vibrating and finally drawing it equal, such that after passing of the concrete paving machine, a completely finished road is created, whereby hereafter one only has to wait for the hardening of the concrete, and eventually provided extension joints will have to be filled.
From the patent documents BE 895.198, BE 1.002.820 and U.S. Pat. No. 3,970,405, it is known to make such concrete paving machines extensible in the direction of a working width, in such a manner that the working width can be adapted to the work to be performed. The extensible embodiments known up to now show the disadvantage that they still are limited in their possibilities and that, in the first place with larger embodiments, for the realization of very wide concrete roads, the transport of such concrete paving machines is very complicated.
From the international patent application WO 96/37661, a concrete paving machine is known the frame of which is extensible perpendicular to the working width, thus, in a direction parallel to the moving direction according to which the concrete paving machine is driven during paving. This known concrete paving machine is provided with support points in the form of track wheels which are attached directly rotatable under the corners of the extensible frame. As a result of such positioning of the track wheels, this concrete paving machine, shows the disadvantage that the track wheels render the accessibility to the tools attached at the frame more difficult. Another disadvantage consists in that unevennesses in the subsoil are directly perceived in the frame, as the track wheels are situated directly under the frame. These unevennesses are perceived even more rapidly in the case that the frame is extended in the aforementioned direction, as this frame, in this extended direction, becomes less rigid and consequently bends more rapidly and every unevenness results in an upward or downward movement at the corner concerned.
The invention aims at a concrete paving machine which is improved.
More particularly, it aims at a concrete paving machine whereby one or both of the aforementioned disadvantages are excluded.
To this aim, the invention relates to a concrete paving machine of the above-mentioned type, with the characteristic that the concrete paving machine is adjustable, extensible respectively, and that it is provided with means as a result of which the adjustment, extension respectively, is optimized. By this optimization is achieved that machines with a large maximum working width still can easily be transported by means of a normal truck and/or that more possibilities in respect to the application of the concrete paving machine are obtained.
In a first preferred form of embodiment, the aforementioned means at least consist of the combination of, on one hand, provisions which allow that the concrete paving machine is adjustable, more particularly, extensible, according to a direction perpendicular to the working width, and, on the other hand, support means in the form of support elements, such as tracks or the like, which are attached on arms extending in respect to the frame and preferably being pivotable in a horizontal plane. Consequently, on one hand, the possibility is obtained to strongly reduce the dimensions of the concrete paving machine in one direction, more particularly, the direction perpendicular to the working width, as a result of which, according to the invention, it becomes possible to transport even very large concrete paving machines on a truck of normal width. On the other hand, the possibility is also created to prolong the concrete paving machine in the direction perpendicular to its working width at random, as a result of which it can easily be provided with additional tools. By combining the extensibility with the use of extending arms, it is obtained that the frame, at its corners, is less sensitive to the unevennesses which are perceived in the support points themselves. As the tracks are attached at extending arms, they form no or little obstruction for the lateral access to tools provided between the frame.
In the case that it can be supposed that the subsoil is even, or in the case that means for automatic height adjustment are provided at the support points, additional tools can be attached between the extending arms.
In a second form of embodiment, the aforementioned means at least consist of provisions which allow that the concrete paving machine is adjustable, more particularly, extensible, at least three times in the direction of its working width, and even better at both sides each time is extensible at least twice, thus, altogether four times. Contrary to the embodiments known up to now, in this manner also the dimension in the direction of the working width can be changed largely, on one hand, with the advantage that a large working range is possible with one and the same machine and, on the other hand, also with the advantage that the length of the concrete paving machine in the transport condition can be optimally reduced.
In the most preferred form of embodiment, a combination is made of, on one hand, provisions which allow that the concrete paving machine is adjustable, more particularly, extensible, in a direction perpendicular to the working width and, on the other hand, provisions which allow that the concrete paving machine is adjustable, more particularly, extensible, in the direction of its working width, in this latter direction preferably at least three times and even better two times at each side.
Preferably, the concrete paving machine will also be extensible in a multiple manner in the direction perpendicular to the working width. More particularly, it is preferred that the lateral flanks of the frame according to the working direction can be extended forward as well as backward. Even more particularly, it shall be possible to extend the frame each time forward as well as backward in a multiple manner.
As usual, the concrete paving machine preferably has a frame at which one or more tools are attached or can be attached, and support means which allow to move this frame. It is noted that the adjustability, extensibility respectively, refers to the actual frame of the concrete paving machine, regardless of which other adjustment means are further provided for positioning the support means at different places. According to the invention, the frame then is composed of different parts which are adjustable, more particularly extensible, in respect to each other, either exclusively in the direction of the working width, or exclusively in a direction perpendicular to the working width, or in both directions.
In a preferred form of embodiment, also one or more of the tools shall be made extensible, either exclusively in the direction of the working width, or exclusively in a direction perpendicular to the working width, or in both directions. As a result, the tools automatically adapt to the working width and/or do not form any obstacle when the concrete paving machine is slid together.
With the aforementioned characteristic that the tools are extensible in both directions, and, thus, also can be slid together, it is meant that the concrete paving machine can be provided with, on one hand, tools which are extensible according to the working width and, on the other hand, tools which are extensible perpendicular to the working width, thus, in the working direction, as well as that the concrete paving machine is provided with one or more tools whereby one and the same tool can perform the two extension movements.
Preferably, the extensible tools are coupled to the extensible parts of the frame, in such a manner that the tools automatically follow the extension movement of the frame.
The concrete paving machine may also be provided with one or more tools which can be detached, which in themselves may either be extensible or not, for example, to be adapted to the working width in mounted condition, in such a manner that the frame, in the detached condition of this tools, can be slid together optimally.
Furthermore, the concrete paving machine according to the invention preferably is provided with support means which consist of support elements which are situated, respectively, in the proximity of the corners of the concrete paving machine, and these support elements are connected to the outermost extensible parts, in such a manner that during extending, sliding together, respectively, of the aforementioned frame the distance between the support elements is also increased, reduced respectively, either exclusively in the direction of the working width, or exclusively in the direction perpendicular to the working width, or in both directions. Hereby, the aforementioned support elements always remain present at the corners of the concrete paving machine, regardless whether this latter is extended or not, as a result of which an optimum stability is guaranteed.
According to the invention, the concrete paving machine preferably has a working width which can be varied between a minimum distance which is smaller than 7 meters and a maximum distance which is larger than 15 meters.
According to a particular characteristic of the invention, the concrete paving machine can be slid together, folded together, respectively, according to the direction perpendicular to its working width, up to a dimension which is smaller than 4 meters, and even better is approximately 3 meters.